Cyclic and Noncyclic Photophosphorylation

It is the synthesis of ATP in conjunction with electron transport, which is only activated by PS-I. CMU, DCMU, and orthophenanthroline are all inhibitors of the process and have no effect on the outcome. Bacteria are the most common organisms that go through this procedure.

There are two photosystems involved in this process: PS-I and PS-II. Furthermore, NADPH is produced throughout the process in addition to ATP. It makes the synthesis of organic compounds and the long-term storage of energy much easier to do.

Photophosphorylation in Both Cyclic and Non-Cyclic Forms

We are all well aware of the entire process of photosynthesis and how it works. It is, in fact, the biological process of transforming light energy into chemical energy that is being discussed. As a result of this process, light energy is caught and put to use in the conversion of carbon dioxide and water into glucose and oxygen. In order for photosynthesis to take place, two processes must take place simultaneously:

Reaction to light

The light reaction takes place in the chloroplast’s grana, which is a small cavity. Light energy is transformed to chemical energy in the form of ATP and NADPH in this process. Photophosphorylation is the term used to describe the addition of phosphate in the presence of light, or the production of ATP by cells, in this extremely light-sensitive activity.

A gloomy reaction

When the dark reaction takes place, the energy that was previously produced by the light reaction is used to fix carbon dioxide into carbohydrates, which is known as carbon fixation. This occurs in the stroma of the chloroplasts, which is where the process takes place.

Photophosphorylation

Photophosphorylation is the process of converting ADP into ATP by harnessing the light energy produced by photosynthesis. It is the process of converting ADP molecules into energy-dense ATP molecules in the presence of light, which results in the production of energy-dense ATP molecules.

There are two types of photophosphorylation

• Photophosphorylation in a cyclic fashion
• Photophosphorylation that is not cyclic

Photophosphorylation in a cyclic fashion

Cyclic photophosphorylation is the term used to describe the photophosphorylation process that results in the movement of electrons in a cyclic way for the purpose of producing ATP molecules.

Plant cells only need to complete the ADP to ATP conversion in order to provide immediate energy to the cells. This action is normally carried out in the thylakoid membrane and makes use of Photosystem I and chlorophyll P700, which are both present in green plants.

Electrons are transported back to P700 during cyclic photophosphorylation instead of going into the NADP from the electron acceptor during the first step of the reaction. The synthesis of ATP molecules is caused by the downward passage of electrons from an acceptor to P700 in the ATP cycle.

Non-cyclic Photophosphorylation

Non-cyclic photophosphorylation is the term used to describe the photophosphorylation process that results in the movement of electrons in a non-cyclic manner for the purpose of synthesizing ATP molecules using the energy provided by excited electrons provided by photosystem II, which is a non-cyclic process.

This mechanism is referred to as non-cyclic photophosphorylation because the electrons that are lost by P680 of Photosystem II are taken up by P700 of Photosystem I and are not restored to P680 as occurs in cyclic photophosphorylation. The whole movement of the electrons occurs in a unidirectional or non-cyclic fashion in this case.

Non-cyclic photophosphorylation occurs when electrons released by P700 are transported by the primary acceptor and then transferred to NADP by the secondary acceptor. In this step, the electrons mix with the protons – H+ – that are created by the splitting up of the water molecule, reducing NADP to NADPH2 and completing the reaction.

Difference Between Cyclic and Noncyclic Photophosphorylation

Conclusion

From the following article we can conclude that PS-I is the only enzyme that activates ATP synthesis in conjunction with electron transport. CMU, DCMU, and orthophenanthroline are all process inhibitors that have no effect on the outcome. Bacteria are the most common organisms to undergo this process.

This process involves two photosystems: PS-I and PS-II. In addition to ATP, NADPH is produced throughout the process. It greatly simplifies the synthesis of organic compounds and the long-term storage of energy.